Riparian Buffer Zones on Selected Rivers in Lower Silesia – an Important Conservation Practice and the Management Strategy in Urban Planning
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6 Contemporary Trends in Geoscience vol . 2 DOI: 10.2478/ctg-2014-0001 Maryna Adamska1 Riparian buffer zones on selected rivers in Lower ¹Department of Geomorphology, Institute of Silesia – an important conservation practice and Geography and Regional Development, University of Wrocław, Uniwersytecki sq. 1, 50-137 Wrocław. the management strategy in urban planning E-mail: [email protected] Key words: Abstract riparian buffer zones, buffer strips, Buffer zones are narrow strips of land lying structure. This will be used to develop clear rivers, vegetation cover, agricultural along the surface water, covered with appro- criteria for the selection of the width of these priately selected vegetation. They separate zones based on land use land management. It aquatic ecosystems from the direct impact of can be used in the implementation of execu- agricultural land and reduce the movement tive acts at different levels of space manage- of nutrients in the environment. In 2008 the ment. Field research consisted of inventory European Commission established require- the extent of riparian buffer strips on select- ments for the implementation of buffer strips ed water courses and photographic documen- along water courses. Poland committed to tation. Species composition of the vegetation the enforcement of these requirements un- forming a buffer zone was identified by us- til 1 January 2012. This was one of the rea- ing Braun-Blanquet method. There was lack sons of this study. The subject of the anal- of continuity of the riparian buffer zones on ysis included the following rivers in Lower investigated rivers. Buffer zones should have Silesia: Smortawa, Krynka, Czarna Woda carefully formulated definition and width be- and the selected transects of Ślęza and Nysa cause they are element of the significant eco- Łużycka. Detailed studies were designed logical value, they perform important envi- to estimate the buffer zones occurring on ronmental protective functions and they are these watercourses and assess these zones’ also the subject of Community law. Contemporary trends in Geoscience vol . 2 7 Introduction Water is a limited resource, so water qual- Main criteria to identify appropriate buffer ity is recently one of the major issues of an width include: resource functional value, in- international concern. (Fielding et al. 2005). tensity of adjacent land use, buffer character- Intensive agriculture and urban development istics and specific buffer functions required. can have a negative impact on stream ecosys- Many agencies rely primarily on a mixture tems. Riparian buffer zones are highly rec- of political acceptability and resource func- ommended to reduce the impact of urbaniza- tional value to determine buffer standards tion and farming on the aquatic ecosystems (Castelle et al. 1994). The most of the buffer and improve the water quality (Agouridis & design studies is concerning on the required Wighman 2010). Riparian buffer zones are width, but the vegetation assemblage, layout, ecological boundaries or ecotones separat- slope of adjacent lands, and length are also ing terrestrial and aquatic ecosystems. They key design parameters. Major buffer strip are important elements, that control sedi- width recommendations for improving or ment and nutrients movement through the protecting water quality tend to be between catchment system. Because of their ecolog- 10 and 30 m (Fischer et al. 2000). ical significance they has become a tool in Vegetation used for buffer designs should proper land use management practices (Burt constitute a mix of trees, shrubs, and her- et al. 2002). These areas between land and a baceous plants that are native to the region surface water body consists of specific type and well-adapted to the climactic, soil, and of vegetation. They act as a barriers and play hydrologic conditions of the site (Fischer & role in many biological, chemical and physical Fischenisch 2000) processes. Riparian buffers protect the water There are few possibilities in designing ripar- from land use practices (Blackwell et al. 1999). ian buffer system. One recommended con- cept consists of 3 zones. The first zone is -un Riparian areas perform multiple ecological managed forest of fast- and slow-growing functions. They regulate sediment removal, water-tolerant trees along the stream bank, control erosion, moderate the shade and wa- the second zone consists of the shrubs and ter temperature, maintain the habitat struc- is located next to the trees. The third zone tural diversity and improve the landscape is occupied by grasses. The perfect solution quality (Broadmeadow & Nisbet 2004). They is when zones are left undisturbed; howev- have been also admitted to be landscape com- er Zone 3 can be mowed or grazed once ful- ponents that promote faunal movement and ly established (Agouridis & Wightman 2010). enhance gene flow (Fisher et al. 2000). The Within each of these plant communities, a influence of the riparian buffer depends on wide variety of species and zone widths can its width, structure, plants composition and be used depending on design requirements the management of this area (Broadmeadow (Schultz et al. 2004). This kind of riparian & Nisbet 2004). buffer system is shown on the figure 1. Fig 1. Riparian buffer system with three zones (based on Schultz et al. 2005, modified). 8 Contemporary Trends in Geoscience vol . 2 Another design model includes 2 zones - buffers. Poland should have included it by the first zone is unmanaged forest adjacent the 1.01.2012. There should have been made to water (left unmanaged to provide shad- changes in Polish law and land use manage- ing and large woody debris to the stream). ment documents. In 19.01.2009 in the reg- The second zone consists of managed forest ulation: Rozporządzenie Rady (we) nr with systematic harvests to remove trees. 73/2009 requirement concerning on imple- The third zone consists of a herbaceous fil- mentation riparian buffers was established. In ter strip that intercepts and slows the usu- Environmental Management Scheme based ally concentrated surface runoff from adja- on Rozporządzenie Rady (we) nr 1257/1999 cent fields and spreads it over a wider front (about support for rural development) and to move more slowly through the riparian rozporządzenie komisji europejskiej buffer (Schultz et al. 2004). 445/2002 9 packets were designed. Packet Sometimes landowners refuse having zone nr 9 is about creating riparian buffer zones. with unmanaged forests because of the trees Although in Polish law there have been some falling into streams and slowing water. As minor changes, they can only be named ‘men- the result the other design project has been tions’. No strict definition of riparian buffer developed - two-zone multi-species ripari- zones have been reported. There are no con- an buffer consisting primarily of a woody ditions referring to an extent, width and com- zone and a grass or grass-forb filter zone. The position of riparian buffer zones. However whole woody zone is managed but may be landowners can receive money support rang- planted to combinations of trees and shrubs ing from 40 zł/100 linear meter. to 110 zł/100 (Schultz et al. 2004). Buffers can also con- linear meter. This amount depends on the sist entirely of grass (grass filter strips), but width of this zone that farmer would consti- fewer benefits are provided by that approach. tute and the class of the soil. Of course there (Agouridis & Wightman 2010). is no authority which could carefully checked In many countries, after recognizing the if there are no frauds in implementing buffer importance of riparian buffers riparian res- zones. Another matter that is worth mention toration and preservation programs have is the fact, that landowner can choose only been established. Poland, as a member of the one from nine packets and still obtain a fi- European Union, committed to the adoption nancial compensation (even if according to of Community law. In European law there the law buffer strips are obligatory). is a requirement to implement the riparian Study area All rivers selected for further analysis are lo- (mezoregion Niemcza-Strzelin Hills) cated within territory of Lower Silesia. The (Kondracki 2002). Ślęza is a left-hand trib- investigation was carried out on five rivers: utary of Odra river. It has length of 78,6 km Krynka, Czarna Woda, Smortawa and select- and the catchment area is 971,7 km2. It has ed transects of Ślęza and Nysa Łużycka. The two maximums of discharge in March and location of the investigated rivers is shown April (Staśko 2005). This is typical for low- on the figure 2. lands rivers. The source of the river is situ- According to regionalization by Kondracki ated in the Niemcza-Strzelin Hills in the vi- (2002) the discussed rivers flows in the terri- cinity of the Bobolice at an altitude of 340 tory of Lower Silesia, the area located within m above sea level. The mouth of the river is two provinces: North European Plain and below the disctrict of Kozanów in Wrocław Bohemian Massif. city in 261,6 km of the Odra river. The investigated transect of Ślęza river (from Czarna Woda flows in area of the makrore- km 14+700 to km 39+300) is situated with- gion Sudeten Foreland (mezoregion Ślęża in makroregion Silesian Lowlands (mezore- Massif) and makroregion Silesian Lowlands gion Wrocławska Plain and Wrocławska (mezoregion Wrocławska Plain) (Kondracki Proglacial Valley) and Sudeten Foreland 2002). It is the right-hand tributary of Contemporary trends in Geoscience vol . 2 Maryna Adamska 9 Riparian buffer zones on selected rivers in Lower Silesia – an important conservation practice and the management strategy in urban planning Bystrzyca river. The source of Czarna Woda river valley is flat-floored and gets wider with is located in the slopes of the Radunia moun- the water course reaching a maximum of 1,5 tain at an altitude of 325 m above sea lev- km width.